1. Field of the Invention
The present invention relates to a system for charging batteries, and more specifically to a system for applying a high voltage finish charge to a battery with an electronic charging device connected in series between a state-of-the-art charging system or alternator and the to-be-charged battery, the finish charge system being designed to use the electric power from the state-of-the-art charger or alternator,and without the use of any other external power source.
2. Description of Prior Art
Most lead-acid batteries are chronically undercharged because they use voltage limited state-of-the-art charging devices that cause the current to decrease at the end of the charging process. When using such systems an extended charging time is required to fully charge the battery, which time is often not taken. In some instances a separate finish charger is connected to a separate power source is applied to finish charging the battery. Many forms of battery finish chargers are known. However, currently chargers that perform the finish charging function are, in general, designed to include both a power generation source, or standard charger, and a finish charge controller. As a result existing finish charger devices duplicate the function of the normal state-of-the-art charger, and a finish charge controller, thereby requiring an excess of equipment and expense for most applications. Alternatively, pulsed charging during the entire lead-acid battery charging cycle has been used to provide a finish charge, but again requires an extended charging time.
It is speculated that sealed lead-acid batteries require a high voltage finish charge due to the interference of the oxygen cycle with the charging of the negative plate. After successive charging of lead-acid batteries that continuously remain in a partially uncharged state, the batteries tend to lose recharging capacity due to crystallization of high resistance lead sulfate at larger or electronically isolated domains. Fortunately, high voltage finish charging also re-charges such high resistance lead sulfate domains to allow the batteries to maintain or recover full voltage capacity. However, most state-of-the-art chargers are voltage limited, and therefore do not have the capability to provide high voltage finish charging.
Lead-acid batteries used in a vehicle for deep cycle use, for example such as recreational vehicles, are charged by the vehicles voltage limited alternator. However, high voltage finish charging is not possible using the vehicles alternator since the rest of the vehicle is connected in series to the alternator and may be damaged if subjected to high finish charging voltages.
Use of pulsed charging generally uses high frequency pulses during the entire charging process. However, such pulsing has limited benefit during bulk charging and increases the amount of time required to charge a battery as compared to a normal state-of-the-art constant current charger. Also, the pulse frequency may be too high to perturb the oxygen cycle at the end of charge. In addition, none of the known finish charging systems draws their power from a state-of-the-art primary charging system or alternator. It is therefore seen that there is a need for a battery charge finishing device for use between a primary charger or alternator power source and a battery (6V, 12V, 24V or other voltage), and more specifically to a system for applying a high voltage finish charge to a battery with an electronic finish charging device having a unique circuit connected in series between such a standard charging system and the to-be-charged battery, the finish charge system being designed to use the electric power from the standard charger or alternator without the use of any other external power source.